How big is Lake Chelan?

Lake Chelan, located in north-central Washington State, is one of the Pacific Northwest’s most stunning natural wonders. Famous for its crystal-clear waters and dramatic mountain backdrop, this glacier-carved lake stretches deep into the Cascade Mountains. But just how big is Lake Chelan? The answer reveals why it’s not only a scenic gem but also a geographical marvel.

Length and Width

Lake Chelan is approximately 50.5 miles (81.3 kilometers) long, making it the longest natural lake in Washington State. It stretches in a northwest-southeast direction, beginning in the remote wilderness of the North Cascades and ending in the town of Chelan. The lake is narrow in most places, with an average width of just 1.3 miles (2.1 kilometers). At its widest point, near the community of Lucerne, the lake spans about 2 miles (3.2 kilometers).

Surface Area

Despite its great length, Lake Chelan is relatively narrow, which gives it a long, fjord-like appearance. The lake covers a surface area of approximately 52.1 square miles (135 square kilometers) or 33,450 acres. While it may not be the largest lake in the Pacific Northwest by area, its elongated shape and extreme depth make it one of the most unique.

Depth and Volume

Perhaps the most remarkable feature of Lake Chelan is its depth. With a maximum depth of 1,486 feet (453 meters), it is the third-deepest freshwater lake in the United States, after Crater Lake in Oregon and Lake Tahoe in California/Nevada. It ranks among the top 30 deepest lakes in the world. What makes this even more impressive is that the lake bed lies 388 feet (118 meters) below sea level, making it one of the few lakes in North America with a floor below sea level.

The vast depth contributes to an immense water volume—15.8 cubic kilometers (3.8 cubic miles)—which supplies clean drinking water to surrounding communities and supports a vibrant ecosystem.

Elevation

Lake Chelan sits at an elevation of about 1,100 feet (335 meters) above sea level at its surface. However, because the lake is dam-controlled at Chelan Dam, the surface level can vary slightly depending on the season and water flow requirements.

Two Basins: Lucerne and Wapato

Lake Chelan is divided into two distinct basins. The upper basin, often referred to as the Lucerne Basin, is the deeper and more remote section of the lake. It extends from Stehekin to Lucerne and is surrounded by steep cliffs and inaccessible terrain. The lower basin, known as the Wapato Basin, runs from Lucerne to the town of Chelan and is shallower, broader, and more developed with homes, vineyards, and marinas.

Final Thoughts

Lake Chelan’s immense size—both in terms of length and depth—makes it a fascinating natural feature of Washington State. Whether you're admiring it from a lakeside winery, exploring it by boat, or hiking the surrounding mountains, the scale of Lake Chelan never fails to impress. Its massive dimensions, crystal-clear waters, and dramatic landscape have made it a beloved destination for generations of nature lovers and adventurers alike.

If you're planning a visit or just curious about the geography of the Pacific Northwest, Lake Chelan is a true giant among the region’s lakes—long, deep, and stunningly beautiful.